Metal complexes

ABSTRACT

The present invention relates to new types of metal complexes. Such compounds can be used as active components (=functional materials) in a series of different types of applications which can be classed within the electronics industry in the widest sense. 
     The inventive compounds are described by the structure 1 and the formulae (1) to (60).

RELATED APPLICATIONS

This application is a national stage application (under 35 U.S.C. 371)of PCT/EP2004/002393 filed Mar. 9, 2004 which claims benefit to Germanapplication 103 10 887.4 filed Mar. 11, 2003.

Organometallic compounds, especially compounds of the d⁸ metals, willfind use in the near future as active components (=functional materials)in a series of different types of applications which can be classedwithin the electronics industry in the widest sense. The organicelectroluminescent devices based on organic components (for a generaldescription of the construction, see U.S. Pat. No. 4,539,507 and U.S.Pat. No. 5,151,629) and their individual components, the organiclight-emitting diodes (OLEDs), have already been introduced onto themarket, as demonstrated by the available car radios having organicdisplays from Pioneer. Further products of this type will shortly beintroduced. In spite of all of this, distinct improvements are stillnecessary here for these displays to provide real competition to thecurrently market-leading liquid crystal displays (LCDs) or to overtakethem.

A development in this direction is the improvement of electron transportmaterials and blue singlet emitters based on metal chelate complexes, ofwhich aluminum and lanthanum chelate complexes in particular are ofinterest here.

A further development which has emerged in recent years is the use oforganometallic complexes which exhibit phosphorescence instead offluorescence [M. A. Baldo, S. Lamansky, P. E. Burrows, M. E. Thompson,S. R. Forrest, Applied Physics Letters, 1999, 75, 4-6].

For theoretical reasons relating to spin probability, up to four timesthe energy efficiency and power efficiency are possible usingorganometallic compounds as phosphorescence emitters. Whether this newdevelopment will establish itself depends strongly upon whethercorresponding device compositions can be found which can also utilizethese advantages (triplet emission=phosphorescence compared to singletemission=fluorescence) in OLEDs. The essential conditions for practicaluse are in particular a long operative lifetime, a high stabilityagainst thermal stress and a low use and operating voltage, in order toenable mobile applications.

In both cases, there has to be efficient chemical access to thecorresponding chelate complexes or organometallic compounds. However, itis of particular interest against the background of the rarity of themetals in the case of ruthenium, osmium, rhodium, iridium and goldcompounds.

The literature has to date described two basic designs of OLEDs whichhave fluorescence or phosphorescence emitters as coloring components:

Type 1 typically has the following layer structure [using the example ofan OLED with phosphorescence emitter: M. E. Thompson et al., Proceedingsof SPIE, 31.07- 02.08.2000, San Diego, USA, Volume 4105, page 119-124]:

-   -   1. Carrier plate=substrate (typically glass or plastics films).    -   2. Transparent anode (typically indium tin oxide, ITO).    -   3. Hole transport layer (HTL): typically based on triarylamine        derivatives.    -   4. Emitter layer (EL): this layer consists either of a        fluorescence emitter or phosphorescence emitter or a matrix        material which is doped with the fluorescence emitter or        phosphorescence emitter.    -   5. Electron transport layer (ETL): usually based on        tris(8-hydroxyquinolinato)aluminum(III) (AlQ₃).    -   6. Cathode: here, generally metals, metal combinations or metal        alloys with a low work function are used, for example Al—Li.

Type 2 typically has the following layer structure [using the example ofan OLED with phosphorescence emitter: T. Tsutsui et al. Jpn. J. Appl.Phys., 1999, 38, L 1502-L 1504]:

-   -   1. Carrier plate=substrate (typically glass or plastics films).    -   2. Transparent anode (typically indium tin oxide, ITO).    -   3. Hole transport layer (HTL): typically based on triarylamine        derivatives.    -   4. Matrix and emitter layer (EL): this layer consists of a        matrix material, for example based on triarylamine derivatives,        which is doped with the fluorescence emitter or phosphorescence        emitter.    -   5. Electron transport/hole-blocking layer (HBL): typically based        on nitrogen heterocycles or based on metal complexes, for        example        bis(2-methyl-8-hydroxyquinolinato)(4-phenylphenolato)-aluminum(III)        (B—AlQ₃).    -   6. Electron transport layer (ETL): usually based on        tris(8-hydroxyquinolinato)aluminum(III) (AlQ₃).    -   7. Cathode: here, generally metals, metal combinations or metal        alloys with a low work function are used, for example Al.

It is also possible to emit the light through a thin transparentcathode. These devices are appropriately (depending on the use)structured, contacted and finally hermetically sealed, since thelifetime of such devices is generally drastically shortened in thepresence of water and/or air.

The characteristic data of the above-described OLEDs show weaknessesincluding the following:

-   -   1. The operative lifetime is in most cases still much too short,        which is an obstacle to introduction of OLEDs on the market.    -   2. It is evident from the efficiency-brightness curves that the        efficiency frequently decreases greatly with increasing        brightness. This means that the high brightnesses needed in        practice can be achieved only by means of a high power        consumption. However, high power consumptions require high        battery power of portable units (mobile phones, laptops, etc.).        Moreover, the high power consumption, which is to a large part        converted to heat, can lead to thermal damage to the display.

In the above-illustrated OLED device, the abovementioned functionmaterials have been or are being intensively optimized.

For some time, (pseudo)octahedral metal complexes in the widest sensehave been used as the ETL (e.g. AlQ₃, see: C. W. Tang et al., AppliedPhys. Lett. 1987, 51(12), 913), HBL (e.g. B—AlQ₃, see: R. Kwong et al.,Applied Physics Letters 2002, 81(1), 162), as the matrix material in theEL (e.g. B—AlQ₃, see: C. H. Chen et al., Proceedings of SPIE—TheInternational Society for Optical Engineering 1998, 3421 (DisplayTechnologies II), 78), as the singlet emitter (e.g. AlQ₃ and othercomplexes, see: S. Tokito et al., Synthetic Metals 2000, 111-112, 393)and as the triplet emitter (e.g. Ir(PPy)₃, see: WO 00/70655; e.g.Ir(TPy)₃ and Ir(BTPy)₃, see: S. Okada et al., Proceedings of the SID,2002, 52.2, 1360). In addition to the individual weaknesses specific toeach material, the known metal complexes have general weaknesses whichwill be presented briefly below:

-   -   1. Many of the known metal complexes, in particular those which        include main group metals such as aluminum, have a sometimes        considerable hydrolysis sensitivity which can have such an        extent that the metal complex is decomposed noticeably even        after short exposure to air. Others, in contrast, for example        the AlQ₃ used as an electron transport material, tends to add on        water.        -   The high hygroscopicity of these and similar aluminum            complexes is a crucial practical disadvantage. AlQ₃ which is            synthesized and stored under standard conditions still            contains, in addition to the hydroxyquinoline ligands, one            molecule of water per complex molecule [cf., for example: H.            Schmidbaur et al., Z. Naturforsch. 1991, 46b, 901-911]. This            is extremely difficult to remove. For use in OLEDs, AlQ₃            therefore has to be purified in a costly and inconvenient            manner in complicated, multistage sublimation processes, and            stored and handled thereafter with exclusion of water in a            protective gas atmosphere. Moreover, large variations in the            quality of individual AlQ₃ batches, and also poor storage            stability were found (see: S. Karg, E-MRS. Konferenz            30.5.00-2.6.00 Strasbourg).    -   2. Many of the known metal complexes have a low thermal        stability. In a vacuum deposition of the metal complexes, this        inevitably always leads to the release of organic pyrolysis        products, some of which considerably reduce the operative        lifetime of the OLEDs even in small amounts.    -   3. Virtually all of the metal complexes which have been detailed        in the literature and have to date found use in OLEDs are        homoleptic, (pseudo)octahedral complexes consisting of a central        metal coordinated to three bidentate ligands. Complexes of this        design can occur in two isomeric forms, the meridional and the        facial isomer. Frequently, there is only a slight thermodynamic        preference for one of the two isomers. Under certain conditions,        for example a certain sublimation temperature, this leads to one        or the other isomer or even mixtures of the two occurring. This        is not desired, since the two isomers often differ distinctly in        their physical properties (emission spectrum, electron and hole        conduction properties, etc.), and the properties of an OLED can        thus deviate distinctly from one another even in the event of        small changes in the preparation process. An example thereof are        the distinctly different properties of mer-AlQ₃ and fac-AlQ₃        which exhibit green and blue photoluminescence respectively        (see M. Coelle, Chemical Communications, 2002, 23, 2908-2909).

There is therefore a need for alternative compounds which do not havethe abovementioned weaknesses but are in no way inferior in efficiencyand emission color to the known metal complexes.

It has now been found that, surprisingly, metal complexes of polypodalligands display outstanding properties when used as the ETL, as the HBL,as the matrix material in the EL, as the singlet emitter and also as thetriplet emitter, the particular specific function being determined bythe suitable selection of the metal and of the suitable accompanyingligand. These compounds form the subject matter of the presentinvention. The compounds feature the following general properties:

-   -   1. In contrast to many known metal complexes which are subject        to partial or complete pyrolytic decomposition in the course of        sublimation, the inventive compounds feature high thermal        stability. When used in appropriate devices, this stability        leads to a distinct increase in the operative lifetime.    -   2. The inventive compounds do not have any noticeable hydrolysis        or hygroscopicity. Storage for several days or weeks with        ingress of air and water vapor does not lead to any changes in        the substances. It was not possible to detect addition of water        to the compounds. This has the advantage that the substances can        be purified, transported, stored and prepared for use under        simpler conditions.    -   3. The inventive compounds, used as the ETL material in the        electroluminescent devices, lead to high efficiencies which are        in particular independent of the current densities used. This        enables very good efficiencies even at high current densities.    -   4. The inventive compounds, used as the HBL material in the        electroluminescent devices, lead to high efficiencies which are        in particular independent of the current densities used. This        enables very good efficiencies even at high current densities,        i.e. high brightnesses. Moreover, the inventive materials are        stable toward holes, which is not the case to a sufficient        degree, for example, for other metal complexes, for example AlQ₃        and analogous compounds (see, for example: Z. Popovic et al.,        Proceedings of SPIE, 1999, 3797, 310-315).    -   5. The inventive compounds, used in electroluminescent devices        as the EL material in pure form or as the matrix material in        combination with a dopant, lead therein to high efficiencies,        the electroluminescent devices being notable for steep        current-voltage curves and particularly for long operative        lifetime.    -   6. The inventive compounds can be prepared with good        reproducibility in reliably high yield and do not have any        variation between batches.    -   7. Some of the inventive compounds have excellent solubility in        organic solvents. This allows these materials to be purified        more readily and also makes them processable from solution by        coating or printing techniques. In the customary processing by        evaporation too, this property is advantageous, since the        purification of the units or of the shadow masks used is thus        considerably eased.

The class of chelate complexes and organometallic compounds of polypodalligands which are described in more detail below and their use asfunctional materials in electrooptical components is novel and has todate not been described in the literature, but their efficientpreparation and availability as pure materials is of great significancefor this purpose.

The present invention thus provides metal complexes of the structure 1

containing at least one metal Met coordinated to a polypodal ligand Ligof the structure 2,

where V is a bridging unit, characterized in that it contains from 1 to80 atoms and the three part-ligands L1, L2 and L3 which may be the sameor different at each instance are covalently bonded to one another, andwhere the three part-ligands L1, L2 and L3 satisfy the structure 3

where Cy1 and Cy2 are the same or different at each instance andcorrespond to substituted or unsubstituted, saturated, unsaturated oraromatic homo- or heterocycles or part-homo- or part-heterocycles of afused system, which are each bonded ionically, covalently orcoordinatively to the metal via a ring atom or via an atom bondedexocyclically to the homo- or heterocycle.

The bridging unit V has from 1 to 80 atoms from main group III, IVand/or V of the elements of the periodic table. These form the basicskeleton of the bridging unit.

The zig-zag line symbol selected above describes here the linkage of Cy1to Cy2 only in general terms. A more detailed description of thepossible linkages of the cycles is given below.

The homo- or heterocycles Cy1 and Cy2 may be linked via a single bond.Moreover, the part-homo- or part-heterocycles Cy1 and Cy2 may be linkedvia a common edge. Furthermore, in addition to the linkage via a singlebond or a common edge, they may be linked to one another viasubstituents on the homo- or heterocycles Cy1 and Cy2 or the part-homo-or part-heterocycles, and thus form a polycyclic, aromatic or aliphaticring system.

The linkages possible in principle will be shown here by way of exampleusing the example of a benzene ring (Cy1) and of a pyridine (Cy2) (seeFIG. 1) without any intention thus to restrict the multitude of allpossible linkages.

Preference is given to inventive compounds of the structure 1,characterized in that they are uncharged i.e. are externallyelectrically neutral.

Preference is given to inventive compounds of the structure 1,characterized in that at least one of the part-ligands L1, L2 and L3,preferably at least two of the part-ligands L1, L2 and L3, and morepreferably all three part-ligands L1, L2 and L3 are singly negativelycharged.

Preference is given to inventive compounds of the structure 1,characterized in that L1=L2=L3.

Preference is likewise given to inventive compounds of the structure 1,characterized in that L2≠L2.

Preference is further given to inventive compounds of the structure 1,characterized in that Cy1 is different from Cy2.

Preference is given to inventive compounds of the structure 1,characterized in that the linking unit V contains, as the linking atom,an element of main group 3, 4 or 5, or a 3- to 6-membered homo- orheterocycle.

Preference is given to inventive compounds of the structure 1,characterized in that the polypodal ligand Lig of the structure 4generates facial coordination geometry on the metal Met.

Preference is likewise given to inventive compounds of the structure 1,characterized in that the polypodal ligand Lig of the structure 5generates meridional coordination geometry on the metal Met.

In the context of this application, facial and meridional coordinationdescribe the environment of the metal Met with the six donor atoms.Facial coordination is present when three identical donor atoms occupy atriangular surface in the (pseudo)octahedral coordination polyhedron,and three identical donor atoms other than the first three occupyanother triangular surface in the (pseudo)octahedral coordinationpolyhedron. Analogously, a meridional coordination is understood to beone in which three identical donor atoms occupy one meridian in the(pseudo)octahedral coordination polyhedron, and three identical donoratoms other than the first three occupy the other meridian in the(pseudo)octahedral coordination polyhedron. This will be shown below byway of example with reference to an example of a coordination of threenitrogen donor atoms and three carbon donor atoms (see FIG. 2). Sincethis description relates to donor atoms and not to the cycles Cy1 andCy2 which provide these donor atoms, the three cycles Cy1 and the threecycles Cy2 may be the same or different at each instance andnevertheless correspond to a facial or meridional coordination in thecontext of this application.

Identical donor atoms are understood to be those which consist of thesame elements (e.g. nitrogen), irrespective of whether these elementsare incorporated within different structures or cyclic structures.

Preference is given in particular to metal complexes according to thecompounds (1) to (8) with facial coordination geometry on the metalaccording to Scheme 1

where the symbols and indices are each defined as follows:

-   M is Al, Ga, In, Tt, P, As, Sb, Bi, Sc, Y, La, V, Nb, Ta, Cr, Mo, W,    Fe, Ru, Os, Co, Rh, Ir, Cu, Au, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er,    Tm, Yb, Lu;-   L is the same or different at each instance and is C, N, P;-   Q is the same or different at each instance and is O, S, Se, Te, N;-   T is the same or different at each instance and is N, P, C;-   X is the same or different at each instance and is CR, N, P;-   Y is the same or different at each instance and is NR¹, O, S, Se,    Te, SO, SeO, TeO, SO₂, SeO₂, TeO₂;-   Z is B, BR, B(CR₂)₃, B(CR₂CR₂)₃, CR, COH, COR¹, CF, CCl, CBr, C—I,    CNR¹ ₂ RC(CR₂)₃, RC(CR₂CR₂)₃, RC(SiR₂)₃, RC(SiR₂CR₂)₃, RC(CR₂SiR₂)₃,    RC(SiR₂SiR₂)₃, cis,cis-1,3,5-cyclohexyl, 1,3,5-(CR₂)₃C₆H₃, SiR,    SiOH, SiOR¹, RSi(CR₂)₃, RSi(CR₂CR₂)₃, RSi(SiR₂)₃, RSi(SiR₂CR₂)₃,    RSi(CR₂SiR₂)₃, RSi(SiR₂SiR₂)₃, N, N(CR₂)₃, N(C═O)₃, N(CR₂CR₂)₃, NO,    P, As, Sb, Bi, PO, AsO, SbO, BiO, PSe, AsSe, SbSe, BiSe, PTe, AsTe,    SbTe, BiTe;-   R is the same or different at each instance and is H, F, Cl, Br, I,    NO₂, CN, a straight-chain or branched or cyclic alkyl or alkoxy    group having from 1 to 20 carbon atoms, in which one or more    nonadjacent CH₂ groups may be replaced by —R¹C═CR¹—, —C≡C—, Si(R¹)₂,    Ge(R¹)₂, Sn(R¹)₂, C═O, C═S, C═Se, C═NR¹, —O—, —S—, —NR¹— or —CONR¹—,    and in which one or more hydrogen atoms may be replaced by F, or an    aryl or heteroaryl group which has from 1 to 14 carbon atoms and may    be substituted by one or more nonaromatic R radicals, where a    plurality of substituents R, both on the same ring and on the two    different rings, together may in turn form a further mono- or    polycyclic, aliphatic or aromatic ring system;-   R¹ is the same or different at each instance and is an aliphatic or    aromatic hydrocarbon radical having from 1 to 20 carbon atoms;-   c is the same or different at each instance and is 0 or 1.

Furthermore, preference is likewise given to the compounds (9) to (12)with meridional coordination geometry on the metal according to Scheme 2

where the symbols and indices M, L, Q, T, X, Y, Z, R, R¹ and c are eachas defined in Scheme 1, and where: n is 1 or 2.

The invention further likewise provides compounds which simultaneouslyhave part-ligands of the type as in compounds (1), (2), (3) and/or (4),i.e. mixed ligand systems. These are described by the formulae (13) to(30) according to Scheme 3:

where the symbols and indices M, L, Q, T, X, Y, Z, R, R¹, c and n areeach as defined in Scheme 1 and 2.

The invention further likewise provides the compounds (31) to (41) whichcontain fused aromatic ligand systems according to Scheme 4:

where the symbols and indices M, L, Q, T, X, Y, Z, R, R¹, c and n areeach as defined in Scheme 1 and 2.

Preference is given to inventive compounds (1) to (41) in which thesymbol M=Al, Ga, In, Sc, Y, La, Ru, Os, Rh, Ir, Au.

Preference is likewise given to inventive compounds (1) to (41) in whichthe symbol L=C, N.

Preference is likewise given to inventive compounds (1) to (41) in whichthe symbol Q=O, S.

Preference is likewise given to inventive compounds (1) to (41) in whichthe symbol T=N.

Preference is likewise given to inventive compounds (1) to (41) in whichthe symbol X═CR, N.

Preference is likewise given to inventive compounds (1) to (41) in whichthe symbol Z=B, CH, CR¹, COR¹, CF, CCl, CBr, SiR, N, P, PO, RC(CR₂)₃,RC(CR₂CR₂)₃, cis,cis-1,3,5-cyclohexyl, RSi (CR₂)₃, RSi(CR₂CR₂)₃,N(CR₂)₃, N(C═O)₃, N(CR₂CR₂)₃.

Preference is likewise given to inventive compounds (1) to (41) in whichthe symbol Y═O, S.

Preference is likewise given to inventive compounds (1) to (41) in whichthe symbol R represents H, F, Cl, Br, I, CN, a straight-chain orbranched or cyclic alkyl or alkoxy group having from 1 to 6 carbon atomsor an aryl or heteroaryl group which has from 3 to 8 carbon atoms andmay be substituted by one or more nonaromatic R radicals, in which aplurality of substituents R, either on the same ring or on the twodifferent rings, together may in turn form a further mono- orpolycyclic, aliphatic or aromatic ring system.

When ring systems are formed by the R radicals in the compounds (1) to(41), they are preferably benzene, 1- or 2-naphthalene, 1-, 2- or9-anthracene, 2-, 3- or 4-pyridine, 2-, 4- or 5-pyrimidine, 2-pyrazine,3- or 4-pyridazine, 2-, 3-, 4-, 5-, 6-, 7- or 8-quinoline, 2- or3-pyrrole, 3-, 4- or 5-pyrazole, 2-, 4- or 5-imidazole, 2- or3-thiophene, 2- or 3-selenophene, 2- or 3-furan, 2-(1,3,4-oxadiazole),indole or carbazole.

The present invention likewise provides the polypodal ligands accordingto compounds (42) to (82), according to Scheme 5:

where the symbols and indices Q, L, T, X, Y, Z, R, R¹, c, n are each asdefined in Scheme 1 and 2.

The inventive compounds (1) to (41) can in principle be prepared byvarious processes, although the process described below has been foundto be particularly suitable.

The present invention therefore further provides a process for preparingthe compounds (1) to (41) by reacting the polypodal ligands of thecompounds (42) to (82) with metal alkoxides of the formula (83), withmetal ketoketonates of the formula (84) and metal halides of the formula(85),

where the symbol R¹ is as defined in Scheme 1 and Hal=F, Cl, Br, I.

This process allows the complexes to be obtained readily in high purity,preferably in a purity of >99%, by ¹H NMR or HPLC.

The synthetic methods illustrated here allow examples including theexamples of compounds (1) to (41) shown below to be prepared.

The above-described inventive compounds, for example compounds accordingto Examples 7, 14, 26, 27, 37, 38, 39 and 41, may find use, for example,as comonomers to obtain corresponding conjugated, semiconjugated or elsenonconjugated polymers, or else as the core of dendrimers, for examplecompounds according to Examples 14 and 26. The appropriatepolymerization is effected preferably via the halogen functionality. Forinstance, they can be polymerized, inter alia, into solublepolyfluorenes (for example according to EP-A-842208 or WO 00/22026),poly-spiro-bifluorenes (for example according to EP-A-707020 orEP-A-894107), poly-para-phenylenes (for example according to WO92/18552), polycarbazoles (for example according to the applications DE10304819.7 and DE 10328627.6), polyvinylcarbazoles or elsepolythiophenes (for example according to EP-A-1028136), or elsecopolymers of a plurality of these units.

The invention thus further provides conjugated, semiconjugated andnonconjugated polymers or dendrimers containing one or more compounds ofthe formula (1) to (41), in which one or more of the above-defined Rradicals is a bond to the polymer or dendrimer.

In addition, the inventive metal complexes may of course also befunctionalized further and thus be converted to extended metalcomplexes. Here, mention may be made as an example of thefunctionalization with arylboronic acids according to SUZUKI or withamines according to HARTWIG-BUCHWALD.

The above-described inventive compounds, polymers, dendrimers or, asdescribed above, compounds which have been further functionalized finduse as active components in electronic components, for example organiclight-emitting diodes (OLEDs), organic integrated circuits (O-ICs),organic field-effect transistors (OFETs), organic thin-film transistors(OTFTs), organic solar cells (O-SCs) or organic laser diodes (O-lasers).

Active components are, for example, charge injection or charge transportmaterials, charge blocking materials and emission materials. For thisfunction, the inventive compounds exhibit particularly good properties,as has already been illustrated above and will be further explainedbelow in more detail.

The invention thus further provides for the use of these compounds inelectronic components.

The invention further provides electronic components, for exampleorganic integrated circuits (O-ICs), organic field-effect transistors(OFETs), organic thin-film transistors (OTFTs), organic solar cells(O-SCs) or organic laser diodes (O-lasers), but in particular organiclight-emitting diodes (OLEDs) which comprise one or more of theinventive compounds, polymers or dendrimers.

The present invention is illustrated in detail by the examples whichfollow of charge transport and hole blocker materials, without anyintention to restrict it thereto. Without inventive activity, thoseskilled in the art can use the remarks to prepare further inventivecomplexes, for example emission materials, or employ the processaccording to the invention.

EXAMPLES Synthesis of Homoleptic Aluminum, Iron and Lanthanum ChelateComplexes with Hexapodal Ligands

Unless stated otherwise, the syntheses which follow were carried outunder a protective gas atmosphere in dried solvents. The reactants werepurchased from ALDRICH or ABCR [2-methoxybenzeneboronic acid,2-bromo-4-fluorophenol, 2-bromo-5-fluorophenol, potassium fluoride(spray-dried), diethylaminosulfur trifluoride (DAST),tri-tert-butylphosphine, palladium(II) acetate, pyridiniumhydrochloride, aluminum triisopropoxide, 10% by weight solution oftris(2-methoxyethanolato)lanthanum(III) in 2-methoxyethanol].Tris(2-bromo-6-pyridyl)phosphine and tris(2-bromo-6-pyridyl)methanolwere prepared as described in WO 98/22148.

Example 1 Tris(2-bromo-6-pyridyl)phosphine oxide

A suspension, heated to boiling, of 50.2 g (100.0 mmol) oftris(2-bromo-6-pyridyl)phosphine in 500 ml of chloroform was admixedwith intensive stirring dropwise with a mixture of 11 ml of 35% byweight H₂O₂ and 50 ml of water, which afforded a clear solution. Afterstirring under reflux for 5 h, the solution was allowed to cool to roomtemperature. The solution was washed with 500 ml of water, and theorganic phase was removed and concentrated to 50 ml under reducedpressure. After standing for 2 h, the precipitated crystals werefiltered off, washed three times with 100 ml of n-hexane and then driedat 70° C. under reduced pressure. The yield at a purity of 99.0% was47.1 g (90.9%).

¹H NMR (CDCl₃) δ [ppm]=8.14 (ddd, ³J_(HP)=5.4 Hz, ³J_(HH)=7.8 Hz,⁴J_(HH)=1.0 Hz, 3H, H-3), 7.69 (ddd, ⁴J_(HP)=4.6 Hz, ³J_(HH)=7.9 Hz,³J_(HH)=7.9 Hz, 3H, H-4), 7.61 (ddd, ⁵J_(HP)=2.1 Hz, ³J_(HH)=7.9 Hz,⁴J_(HH)=1.0 Hz, 3H, H-5).

³¹P{¹H} NMR (CDCl₃) δ [ppm]=11.8 (s).

Example 2 Tris(6-(2-methoxyphenyl)-2-pyridyl)phosphine oxide

An efficiently stirred suspension of 38.8 g (75.0 mmol) oftris(2-bromo-6-pyridyl)phosphine oxide, 51.3 g (337.5 mmol) of2-methoxybenzeneboronic acid and 43.1 g (742.5 mmol) of potassiumfluoride in 750 ml of anhydrous THF was admixed with 593 mg (2.93 mmol)of tri-tert-butylphosphine and then with 505 mg (2.25 mmol) ofpalladium(II) acetate, and subsequently heated under reflux for 16 h.After cooling, the reaction mixture was admixed with 1500 ml of ethylacetate and 1000 ml of water. The organic phase was removed, washedtwice with 500 ml of water and once with 500 ml of sat. sodium chloridesolution, and subsequently dried over magnesium sulfate. After theorganic phase had been concentrated under reduced pressure (end pressure1 mbar, temperature 90° C.), 44.3 g (98.5%) of a pale yellow highlyviscous oil remained, which was reacted further without purification.

¹H NMR (CDCl₃) δ [ppm]=8.14 (ddd, 3H), 8.02 (ddd, 3H), 7.85 (dd, 3H),7.76 (ddd, 3H), 7.30 (ddd, 3H), 6.94 (dd, 3H), 6.87 (ddd, 3H), 3.10 (s,9H CH₃).

³¹P{H} NMR (CDCl₃): δ [ppm]=14.0 (s).

Example 3 Tris(6-(2-hydroxyphenyl)-2-pyridyl)phosphine oxide, (PPL-01)

A mixture of 30.0 g (50 mmol) oftris(6-(2-methoxyphenyl)-2-pyridyl)phosphine oxide and 104.0 g (900mmol) of pyridinium hydrochloride was stirred at 130° C. for 12 h. Afterthe melt had been cooled to 80° C., it was admixed with 300 ml of waterand then with a solution of 44.9 g (800 mmol) of potassium hydroxide in100 ml of water. The aqueous phase was extracted three times with 500 mlof dichloromethane. The combined organic phases were washed three timeswith 500 ml of water. After the organic phase had been dried overmagnesium sulfate and the dichloromethane had been removed, the oilyresidue was taken up in 100 ml of methyl tert-butyl ether and admixedwith 100 ml of n-heptane. After standing for 12 h, the colorlesscrystals were filtered off with suction and recrystallized from methyltert-butyl ether/n-heptane. The yield was 10.9 g (39.1%) at a purity ofgreater than 99.0% by ¹H NMR.

¹H NMR (CDCl₃) δ [ppm]=14.33 (s, 3H, OH), 8.45 (m, 3H), 8.13 (m, 3H),7.88 (m, 3H), 7.61 (m, 3H), 7.23 (m, 3H), 7.01 (m, 3H), 6.90 (m, 3H).

³¹P{¹H} NMR (CDCl₃) δ [ppm]=10.3 (s).

Example 4 Tris(2-bromo-6-pyridyl)fluoromethane

A solution of 50.0 g (100 mmol) of tris(2-bromo-6-pyridyl)methanol in750 ml of dichloromethane was admixed with good stirring dropwise with47.3 ml (400 mmol) of diethylaminosulfur trifluoride. Subsequently, thereaction mixture was heated under reflux for 30 min, then cooled to 5°C., and admixed with good stirring (highly exothermic!!!) with 300 ml ofwater and then with a solution of 64.0 g (1600 mmol) of sodium hydroxidein 600 ml of water (highly exothermic!!!). The organic phase wasremoved, the aqueous phase was washed twice with 200 ml ofdichloromethane, and the combined organic phases were dried over calciumchloride and subsequently freed of dichloromethane. The remainingred-brown crystal slurry was taken up in 100 ml of methanol and filteredoff. After washing with methanol, the colorless to beige crystals weredried under reduced pressure. The yield was 47.4 g (91.3%) at a purityof greater than 99.0% by ¹H NMR.

¹H NMR (CDCl₃): δ [ppm]=7.58 (ddd, ³J_(HH)=7.7 Hz, ³J_(HH)=7.7 Hz,⁵J_(FH)=0.7 Hz, 1H, H-4), 7.53 (dd, ³J_(HH)=7.7 Hz, ⁴J_(HH)=0.7 Hz, 1H,H-3), 7.45 (ddd, ³J_(HH)=7.7 Hz, ⁴J_(HH)=0.7 Hz, ⁴J_(FH)=0.9 Hz, 1H,H-5).

¹⁹F{¹H} NMR (CDCl₃) δ [ppm]=−146.2 (s).

Example 5 2-Bromo-4-fluoro-1-(tetrahydropyran-2-yloxy)benzene

A mixture of 478.0 ml (5.24 mol) of 3,4-dihydropyran and 750 ml ofdichloromethane was admixed with 65.4 g (260 mmol) of pyridiniump-toluenesulfonate. Subsequently, a solution of 500.0 g (2.62 mmol) of2-bromo-4-fluorophenol in 500 ml of dichloromethane was added dropwise.After stirring for 24 h, the reaction mixture was admixed with asolution of 50 g of potassium carbonate in 500 ml of water, and thenwith 500 ml of saturated sodium chloride solution. The organic phase wasremoved, dried over potassium carbonate and, after freeing it of thesolvent and potassium carbonate, fractionally distilled (approx. 1 mbar,top temperature from 79 to 82° C.) by means of a Vigreux column (40 cm).The product was obtained as a colorless, low-viscosity oil. The yieldwas 520.5 g (72.2%) at a purity of greater than 98.0% by ¹H NMR.

¹H NMR (CDCl₃): δ [ppm]=7.27 (dd, ³J_(FH)=8.0 Hz, ⁴J_(HH)=3.0 Hz, 1H,H-3), 7.10 (dd, ³J_(HH)=9.7 Hz, ⁴J_(FH)=5.0 Hz, 1H, H-6), 6.93 (ddd,³J_(HH)=9.7 Hz, ³J_(FH)=8.0 Hz, ⁴J_(HH)=3.2 Hz, 1H, H-5), 5.39 (m, 1H,CH), 3.88 (m, 1H, CH₂O), 3.59 (m, 1H, CH₂O), 2.12-1.53 (m, 6H, CH₂).

¹⁹F{¹H} NMR (CDCl₃): δ [ppm]=−121.1 (s).

Example 6 5-Fluoro-2-(tetrahydropyran-2-yloxy)benzeneboronic acid

48.6 g (2.00 mol) of magnesium and 510 g (1.85 mol) of2-bromo-4-fluoro-1-(tetrahydropyran-2-yloxy)benzene in 1250 ml of THFwere used to prepare a Grignard reagent. This Grignard reagent wasslowly added dropwise at −78° C. to a mixture of 241.6 ml (2.00 mol) oftrimethyl borate in 500 ml of THF. On completion of addition, thereaction mixture was allowed to warm to room temperature and washydrolyzed by addition of 100 ml of saturated potassium carbonatesolution and 1000 ml of water. The organic phase was washed withsaturated sodium chloride, solution. (1×500 ml) and subsequentlyconcentrated to dryness. The yield was 428.2 g (1.78 mol), and theproduct was obtained as a waxy solid which contained varying proportionsof boronic anhydride and borinic acids and was used in the followingstage without further purification.

Example 7 Tris(6-(5-fluoro-2-hydroxyphenyl)-2-pyridyl]fluoromethane,(PPL-02)

Procedure of the Suzuki coupling analogous to Example 2, for which 51.9g (100 mmol) of tris(2-bromo-6-pyridyl)fluoromethane (Example 4), 108.0g (450 mmol) of 5-fluoro-2-(tetrahydropyran-2-yloxy)benzeneboronic acid(Example 6), 57.5 g (990 mmol) of potassium fluoride, 1.35 g (6 mmol) ofpalladium(II) acetate and 1.8 ml (8 mmol) of tri-tert-butylphosphine in1000 ml of THF were used.

After 6 h under reflux, the reaction mixture was freed of the THF on arotary evaporator, and the slurrylike residue was taken up in 1000 ml ofmethanol, admixed with a mixture of 300 ml of water and 55 ml of 5N HCland subsequently stirred at 50° C. for a further 3 h. The resultingcrystal slurry was filtered off with suction (P3), washed with methanoland dried. Recrystallization from a little chloroform with addition ofmethanol gave 53.2 g (89.0%) of the product in the form of colorlesscrystals having a purity of greater than 99.0% by ¹H NMR.

¹H NMR (CDCl₃): δ [ppm]=12.34 (s, 3H, OH), 7.99 (dd, ³J_(HH)=8.4 Hz,³J_(HH)=8.4 Hz, 3H, H-4-Py), 7.86 (d, ³J_(HH)=8.4 Hz, 3H, H-5-Py), 7.79(d, ³J_(HH)=8.4 Hz, 3H, H-3-Py), 7.45 (dd, ³J_(HH)=9.4 Hz, ⁴J_(FH)=3.0Hz, 3H, H-3), 6.95 (ddd, ³J_(HH)=9.4 Hz, ³J_(FH)=8.0 Hz, ⁴J_(HH)=3.0 Hz,3H, H-4), 6.76 (dd, ³J_(FH)=9.0 Hz, ⁴J_(HH)=3.0 Hz, 3H, H-6).

¹⁹F{¹H} NMR (CDCl₃): δ [ppm]=−144.9 (s, 1F), −125.9 (s, 3F).

Example 8 2-Bromo-5-fluoro-1-(tetrahydropyran-2-yloxy)benzene

Procedure analogous to Example 5. Use of 478.0 ml (5.24 mol) of3,4-dihydropyran, 65.4 g (260 mmol) of pyridinium p-toluenesulfonate and500.0 g (2.62 mmol) of 2-bromo-5-fluorophenol. The yield was 562.2 g(78.0%) at a purity of greater than 98.0% by ¹H NMR.

¹H NMR (CDCl₃): δ [ppm]=7.45 (dd, ³J_(HH)=9.1 Hz, ⁴J_(FH)=6.4 Hz, 1H,H-3), 6.92 (dd, ³J_(FH)=10.7 Hz, ⁴J_(FH)=2.7 Hz, 1H, H-6), 6.60 (ddd,³J_(HH)=9.1 Hz, ³J_(FH)=8.7 Hz, ⁴J_(HH)=2.7 Hz, 1H, H-4), 5.46 (m, 1H,CH), 3.84 (m, 1H, CH₂O), 3.62 (m, 1H, CH₂O), 2.14-1.56 (m, 6H, CH₂).

¹⁹F{¹H} NMR (CDCl₃) δ [ppm]=−112.7 (s).

Example 9 4-Fluoro-2-(tetrahydropyran-2-yloxy)benzeneboronic acid

Procedure analogous to Example 6. Use of 48.6 g (2.00 mol) of magnesium,510 g (1.85 mol) of 2-bromo-5-fluoro-1-(tetrahydropyran-2-yloxy)benzeneand 241.6 ml (2.00 mol) of trimethyl borate. The yield was 434.5 g (1.81mol), and the product was obtained as a waxy solid which containedvarying proportions of boronic anhydrides and borinic acids and was usedin the following stage without further purification.

Example 10 Tris(6-(4-fluoro-2-hydroxyphenyl)-2-pyridyl)fluoromethane,(PPL-03)

Procedure analogous to Example 7. Use of 51.9 g (100 mmol) oftris(2-bromo-6-pyridyl)fluoromethane (Example 4), 108.0 g (450 mmol) of4-fluoro-2-(tetrahydropyran-2-yloxy)benzeneboronic acid (Example 9),57.5 g (990 mmol) of potassium fluoride, 1.35 g (6 mmol) ofpalladium(II) acetate and 1.8 ml (8 mmol) of tri-tert-butylphosphine.The yield was 56.9 g (95.5%) of the product in the form of colorlesscrystals having a purity of greater than 99.0% by ¹H NMR.

¹H NMR (CDCl₃): δ [ppm]=13.01 (s, 3H, OH), 7.96 (dd, ³J_(HH)=8.2 Hz,³J_(HH)=8.2 Hz, 3H, H-4-Py), 7.86 (d, ³J_(HH)=8.2 Hz, 3H, H-5-Py), 7.75(dd, ³J_(HH)=9.4 Hz, ⁴J_(FH)=6.4 Hz, 3H, H-6), 7.52 (d, ³J_(HH)=8.2 Hz,3H, H-3-Py), 6.59 (ddd, ³J_(HH)=9.4 Hz, ³J_(FH)=8.0 Hz, ⁴J_(HH)=2.7 Hz,3H, H-5), 6.51 (dd, ³J_(FH)=10.7 Hz, ⁴J_(HH)=2.7 Hz, 3H, H-3).

¹⁹F{¹H} NMR (CDCl₃) δ [ppm]=−144.7 (s, 1F), −108.6 (s, 3F).

Example 11Mono[tris(6-(2-oxyphenyl)-2-pyridyl)phosphinoxido]aluminum(III);Al—PPL-01

A solution of 5.58 g (10 mmol) oftris(6-(2-hydroxyphenyl)-2-pyridyl)phosphine oxide (Example 3) in 100 mlof toluene was admixed at 80° C. over 30 min with a solution of 2.04 g(10 mmol) of tris(isopropanolato)aluminum(III) in 50 ml of toluene. Thereaction mixture was heated under reflux for a further 3 h. Aftercooling to room temperature, the colorless precipitate was filtered offwith suction, washed with toluene (1×25 ml) and dried. Repeatedrecrystallization from DMSO gave 5.03 g (86.5%) of the complex at apurity of 99.8% by HPLC.

MS (FAB): m/e=582.

Example 12Mono[tris(6-(2-oxyphenyl)-2-pyridyl)phosphinoxido]lanthanum(III);La—PPL-01

A solution of 5.58 g (10 mmol) oftris(6-(2-hydroxyphenyl)-2-pyridyl)phosphine oxide (Example 3) in 100 mlof toluene was admixed at 80° C. over 30 min with 36.4 ml (10 mmol) of a10% by weight solution of tris(2-methoxyethanolato)lanthanum(III) in2-methoxyethanol. The reaction mixture was heated under reflux for afurther 3 h. After cooling to room temperature, the colorlessprecipitate was filtered off with suction, washed with toluene (1×25 ml)and dried. Repeated recrystallization from DMSO gave 5.68 g (81.7%) ofthe complex at a purity of 99.8% by HPLC.

MS (FAB): m/e=693.

Example 13Mono[tris(6-(5-fluoro-2-oxyphenyl)-2-pyridyl)fluoromethanato]aluminum(III);Al—PPL-02

A solution of 5.96 g (10 mmol) oftris(6-(5-fluoro-2-hydroxyphenyl)-2-pyridyl)fluoromethane (Example 7) in200 ml of THF was admixed first with 19.4 ml (240 mmol) of pyridine andthen, dropwise at room temperature over 30 min, with a solution of 20 mlof 0.5 N aluminum chloride solution in ethanol. The reaction mixture washeated to reflux for a further 3 h. After cooling to room temperature,the colorless precipitate was filtered off with suction, washed with THF(3×50 ml) and ethanol (3×50 ml) and then dried. Repeatedrecrystallization from DMSO (200 ml) gave 5.59 g (90.3%) of the paleyellow complex at a purity of 99.9% by ¹H NMR.

¹H NMR (DMSO-d6) δ[ppm]=8.23 (dd, ³J_(HH)=8.0 Hz, ³J_(HH)=8.0 Hz, 3H,H-4-Py), 8.17 (d, ³J_(HH)=8.0 Hz, 3H, H-5-Py), 7.99 (dd, ³J_(HH)=8.0 Hz,⁴J_(FH)=3.4 Hz, 3H, H-3-Py), 7.69 (dd, ³J_(HH)=9.0 Hz, ⁴J_(FH)=3.0 Hz,3H, H-3), 7.03 (ddd, ³J_(HH)=9.0 Hz, ³J_(FH)=9.0 Hz, ⁴J_(HH)=3.4 Hz, 3H,H-4), 6.19 (dd, ³J_(FH)=9.0 Hz, ⁴J_(HH)=3.4 Hz, 3H, H-6).

¹⁹F{¹H} NMR (DMSO-d6): δ [ppm]=−177.5 (s, 1F), −128.6 (s, 3F).

T_(g): 178° C.

Example 14Mono[tris(6-(5-fluoro-2-oxyphenyl)-2-pyridyl)fluoromethanato]iron(III);Fe—PPL2

Procedure analogous to Example 13. Use of 5.96 g (10 mmol) oftris(6-(5-fluoro-2-hydroxyphenyl)-2-pyridyl)fluoromethane (Example 10)and 20 ml of a 0.5N iron(III) chloride 6H₂O solution in ethanol.Repeated recrystallization from DMSO (200 ml) with addition of 100 ml ofethanol after cooling of the solution to 120° C. gave 5.39 g (83.1%) ofthe black complex. MS (FAB): m/e=648.

Example 15Mono[tris(6-(4-fluoro-2-oxyphenyl)-2-pyridyl)fluoromethanato]aluminum(III);Al—PPL3

Procedure analogous to Example 13. Use of 5.96 g (10 mmol) oftris(6-(4-fluoro-2-hydroxyphenyl)-2-pyridyl)fluoromethane (Example 10)and 20 ml of a 0.5N aluminum chloride solution in ethanol. Repeatedrecrystallization from DMSO (200 ml) gave 5.32 g (86.0%) of the paleyellow complex at a purity of 99.9% by ¹H NMR.

¹H NMR (DMSO-d6): δ [ppm]=8.24 (dd, ³J_(HH)=8.0 Hz, ³J_(HH)=8.0 Hz, 3H,H-4-Py), 8.15 (d, ³J_(HH)=8.0 Hz, 3H, H-5-Py), 7.97 (dd, ³J_(HH)=8.0 Hz,⁴J_(FH)=3.4 Hz, 3H, H-3-Py), 7.92 (dd, ³J_(HH)=9.0 Hz, ⁴J_(FH)=7.0 Hz,3H, H-6), 6.53 (ddd, ³J_(HH)=8.7 Hz, ³J_(FH)=8.7 Hz, ⁴J_(HH)=2.7 Hz, 3H,H-5), 5.92 (dd, ³J_(FH)=11.4 Hz, ⁴J_(HH)=2.7 Hz, 3H, H-3).

¹⁹F{¹H} NMR (DMSO-d6) δ [ppm]=−178.4 (s, 1F), −109.5 (s, 3F).

T_(g): 197° C.

Comparative Experiments on Hydrolysis Stability

Example 16

In a comparative experiment, the hydrolysis stability of the polypodalaluminum complexmono[tris(6-(5-fluoro-2-oxyphenyl)-2-pyridyl)fluoromethanato]-aluminum(III)(Al—PPL-2), according to Example 13, was compared with that of thestructurally analogous but not polypodal varianttris[5-fluoro-2-oxyphenyl)-2-pyridylato]aluminum(III), which isdescribed in the application JP 09176629 A2 as an OLED material. To thisend, a 10 mmolar solution of both complexes in dry DMSO-d6 was preparedunder an inert gas atmosphere. This solution was characterized with theaid of ¹H NMR and of ¹⁹F NMR spectroscopy. Subsequently, these solutionswere admixed at room temperature with the 1000 molar amount of waterand, after standing for 10 min, characterized again with the aid of ¹HNMR and of ¹⁹F NMR spectroscopy. In the case of the polypodal aluminumcomplexmono[tris(6-(5-fluoro-2-oxyphenyl)-2-pyridyl)fluoromethanato]aluminum(III)(Al—PPL-2) according to Example 13, no change whatsoever in the NMRcould be detected. In contrast, in the case of the non-polypodaltris(5-fluoro-2-oxyphenyl)-2-pyridylato)aluminum(III), fulldecomposition of the complex was observed, recognizable by appearance ofthe proton and fluorine signals of the noncoordinated ligands. Evenafter heating the above-described hydrolysis mixture to 180° C. for fivehours, no sign of decomposition of the polypodal aluminum complexAl—PPL-2 according to Example 13 could be detected. This comparativeexperiment demonstrates clearly the excellent hydrolysis stability ofthe inventive polypodal complexes.

Production and Characterization of Organic Electroluminescent Deviceswhich Comprise Inventive Compounds

The OLEDs are produced by a general process which was optimized in theindividual case to the particular circumstances (for example layerthickness variation to optimize the efficiency and the color). Inventiveelectroluminescent devices can be prepared as described, for example, inDE 10330761.3 or else DE 10261545.4.

Example 17 Device Structure

The examples which follow show the results of various OLEDs, both withphosphorescence emitters and fluorescence emitters, in which inventivecompounds were used in the first case as hole blocking materials, andBCP and BAlq as comparative materials (see Table 1). In the second case,an inventive compound was used as the electron transport material andAlQ₃ as the corresponding comparative material (see Table 2). The basicstructure, the materials and layer thicknesses used (apart from theHBLs) were identical for better comparability.

According to the abovementioned general process, phosphorescent OLEDswith the following structure were obtained:

PEDOT (HIL) 60 nm (spin coated from water; purchased as Baytron P fromH. C. Starck; poly(3,4-ethylenedioxy- 2,5-thiophene)) NaphDATA (HTL) 20nm (applied by vapor deposition; purchased from SynTec; 4,4′,4″-tris(N-1-naphthyl-N-phenylamino)triphenyl- amine) S-TAD (HTL) 20 nm (applied byvapor deposition; prepared according to WO 99/12888;2,2′,7,7′-tetrakis(diphenylamino)spiro- bifluorene) (EML) materials andlayer thicknesses: see Table 1 or 2 (HBL) if present, materials andlayer thicknesses: see Table 1 (ETL) materials and layer thicknesses:see Table 1 or 2 Ba—Al (cathode) 3 nm of Ba, 150 nm of Al thereon.

These OLEDs which were yet to be optimized were characterized in astandard manner; for this purpose, the electroluminescence spectra, theefficiency (measured in cd/A), the power efficiency (measured in lm/W)were determined as a function of the brightness and the lifetime. Thelifetime is defined as the time after which the starting brightness ofthe OLED has fallen by half at a constant current density of 10 mA/cm².

Table 1 compiles the results of the inventive OLEDs with use of thephosphorescence emitter Ir(PPY)₃ doped to an extent of 10% in CBP(4,4′-bis(carbazol-9-yl)biphenyl) and use of the complex Al—PPL2according to Example 13 as a hole blocking material, and a comparativeexample (with BAlq). Table 1 shows merely the hole blocking layer andthe electron transport layer (composition and layer thickness). Theelectron transport material used was AlQ₃(tris(8-hydroxyquinolinato)aluminum(III)), purchased from SynTec. Theother layers correspond to the abovementioned structure.

Table 2 compiles the results of the inventive OLEDs with use of afluorescence emitter and use of the complex Al—PPL2 according to Example13 as the electron transport material, and some comparative examples(with the electron transport material AlQ₃). Table 2 shows merely theemitter layer and the electron transport layer (composition and layerthickness). The other layers correspond to the abovementioned structure.

The abbreviations used above and in Tables 1 and 2 correspond to thefollowing compounds:

TABLE 1

Max. Voltage Power efficiency Lifetime efficiency (V) at (lm/W) at max.(h) at 10 Example HBL ETL (cd/A) 100 cd/m² efficiency CIE (x, y) mA/cm₂Example T1 Al-PPL2 AlQ₃ 30.0 5.1 16.5 0.32/0.62 600 (10 nm) (20 nm)Example T2 BAlq AlQ₃ 18.3 5.1 8.5 0.32/0.62 250 (comparison) (10 nm) (20nm) Example T3 Al-PPL2 — 22.9 3.2 23.2 0.32/0.62 290 (20 nm) Example T4BAlq — 16.5 5.3 8.8 0.32/0.62 180 (comparison) (20 nm)

TABLE 2 Max. Power efficiency efficiency Voltage (V) (lm/W) at max.Lifetime (h) Example EML ETL (cd/A) at 100 cd/m² efficiency CIE (x, y)at 10 mA/cm₂ Example S1 S-DPVBi Al-PPL2 4.7 3.6 3.8 0.16/0.20 800 (30nm) (10 nm) Example S2 S-DPVBi Al-Q₃ 3.9 4.9 2.4 0.16/0.20 640(comparison) (30 nm) (10 nm)

Table 1 shows that the use of Al—PPL2 in phosphorescent OLEDs as thehole blocking material distinctly increases the efficiency, inparticular the power efficiency, of the OLEDs in comparison to BAlq, andtypically a doubling of the power efficiency was observed. At the sametime, the lifetime was also distinctly improved. The examples show thateven the electron transport layer can be left out, which constitutes adistinct simplification of the device structure.

In the case of the use of Al—PPL2 as the electron transport material influorescent OLEDs, the efficiency, power efficiency and lifetime arelikewise distinctly improved, as can be taken from Table 2.

In summary, it can be stated that phosphorescent and fluorescent OLEDswhich comprise inventive compounds such as Al—PPL2 as hole blockingmaterials or electron transport materials have high efficiencies withsimultaneously long lifetimes and low operating voltages, as can betaken readily from the examples listed in Tables 1 and 2.

1. A compound of the structure 1,

containing at least one metal Met, wherein Met is a transition metal,Group III metal or f-block metal, coordinated to a polypodal ligand Ligof the structure 2,

where V is a bridging unit, characterized in that the three part-ligandsL1, L2 and L3 which may be the same or different at each instance arecovalently bonded to one another, and where V is CR, COH, COR¹, CF, CCl,CBr, C—I, CN(R¹)₂, RC(CR₂)₃, RC(SiR₂)₃; R is the same or different ateach instance and is H, F, Cl, Br, I, NO₂, CN, a straight-chain orbranched or cyclic alkyl or alkoxy group having from 1 to 20 carbonatoms, in which one or more nonadjacent CH₂ groups may be replaced by—R¹C═CR¹—, —C≡C—, Si(R¹)₂, Ge(R¹)₂, Sn(R¹)₂, C═O, C═S, C═Se, C═NR¹, —O—,—S—, —NR¹— or —CONR¹—, and in which one or more hydrogen atoms may bereplaced by F, or an aryl or heteroaryl group which has from 1 to 14carbon atoms and may be substituted by one or more nonaromatic Rradicals, where a plurality of substituents R, both on the same ring andon the two different rings, together may in turn form a further mono- orpolycyclic, aliphatic or aromatic ring system; R¹ is the same ordifferent at each instance and is an aliphatic or aromatic hydrocarbonradical having from 1 to 20 carbon atoms; and where the threepart-ligands L1, L2 and L3 satisfy the structure 3

where Cy1 is a substituted or unsubstituted 2-pyridyl connected to V andCy2 are the same or different at each instance and correspond tosubstituted or unsubstituted aromatic homocycles of carbon orsubstituted or unsubstituted aromatic heterocycles, which are eachbonded ionically, covalently or coordinatively to the metal via a ringatom or via an atom bonded exocyclically to the homo- or heterocycle,the zig-zag line is a direct bond linkage between Cy1 to Cy2, and thatthe compounds of the structure 1 are uncharged.
 2. The compound asclaimed in claim 1, wherein L1=L2=L3.
 3. The compound as claimed inclaim 1, wherein the polypodal ligand Lig of the structure 4 generatesfacial coordination geometry on the metal Met


4. A metal complex which comprises the compound as claimed in claim 1,selected from the compounds (1)¹ and (2)¹,

where the symbols and indices are each defined as follows: M is Al, Ga,In, Tt, P, As, Sb, Bi, Sc, Y, La, V, Nb, Ta, Cr, Mo, W, Fe, Ru, Os, Co,Rh, Ir, Cu, Au, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu; X isthe same or different at each instance and is CR, N or P; Y is the sameor different at each instance and is NR¹, O, S, Se, Te, SO, SeO, TeO,SO₂, SeO₂ or TeO₂; Z is the same as defined for V R is the same ordifferent at each instance and is H, F, Cl, Br, I, NO₂, CN, astraight-chain or branched or cyclic alkyl or alkoxy group having from 1to 20 carbon atoms, in which one or more nonadjacent CH₂ groups may bereplaced by —R¹C═CR¹—, —C≡C—, Si(R¹)₂, Ge(R¹)₂, Sn(R¹)₂, C═O, C═S, C═Se,C═NR¹, —O—, —S—, —NR¹— or —CONR¹—, and in which one or more hydrogenatoms may be replaced by F, or an aryl or heteroaryl group which hasfrom 1 to 14 carbon atoms and may be substituted by one or morenonaromatic R radicals, where a plurality of substituents R, both on thesame ring and on the two different rings, together may in turn form afurther mono- or polycyclic, aliphatic or aromatic ring system; and R¹is the same or different at each instance and is an aliphatic oraromatic hydrocarbon radical having from 1 to 20 carbon atoms and c isthe same or different at each instance and is 0 or
 1. 5. The metalcomplex as claimed in claim 4, wherein the symbol M=Al, Ga, In, Sc, Y,La, Ru, Os, Rh, Ir or Au.
 6. The metal complex as claimed in claim 4,wherein the symbol X═CR.
 7. The metal complex as claimed in claim 4,wherein the symbol Y═O or S.
 8. The metal complex as claimed in claim 4,wherein the symbol R═H, F, Cl, Br, I, CN, a straight-chain or branchedor cyclic alkyl or alkoxy group having from 1 to 6 carbon atoms or anaryl or heteroaryl group which has from 3 to 8 carbon atoms and may besubstituted by one or more nonaromatic R radicals, in which a pluralityof substituents R, either on the same ring or on the two differentrings, together may in turn form a further mono- or polycyclic,aliphatic or aromatic ring system.
 9. The compound as claimed in claim1, wherein the compound has a purity (determined by means of ¹H NMRand/or HPLC) is more than 99%.
 10. Conjugated, semiconjugated ornonconjugated polymers or dendrimers containing one or more compounds ofthe structure (1) as claimed in claim
 1. 11. Conjugated, semiconjugatedor nonconjugated polymers or dendrimers as claimed in claim 10, in whichone or more of the R radicals is a bond to the polymer or dendrimer andR is the same or different at each instance and is H, F, Cl, Br, I, NO₂,CN, a straight-chain or branched or cyclic alkyl or alkoxy group havingfrom 1 to 20 carbon atoms, in which one or more nonadjacent CH₂ groupsmay be replaced by —R¹C═CR¹—, —C≡C—, Si(R¹)₂, Ge(R¹)₂, Sn(R¹)₂, C═O,C═S, C═Se, C═NR¹, —O—, —S—, —NR¹— or —CONR¹—, and in which one or morehydrogen atoms may be replaced by F, or an aryl or heteroaryl groupwhich has from 1 to 14 carbon atoms and may be substituted by one ormore nonaromatic R radicals, where a plurality of substituents R, bothon the same ring and on the two different rings, together may in turnform a further mono- or polycyclic, aliphatic or aromatic ring system;and R¹ is the same or different at each instance and is an aliphatic oraromatic hydrocarbon radical having from 1 to 20 carbon atoms. 12.Polymers as claimed in claim 10, characterized in that the polymer isselected from the group of polyfluorenes, poly-spiro-bifluorenes,poly-para-phenylenes, polycarbazoles, polyvinylcarbazoles,polythiophenes, or else from copolymers which have a plurality of theunits specified here.
 13. Polymers as claimed in claim 10, characterizedin that the polymer is soluble in organic solvents.
 14. An electroniccomponent comprising at least one compound as claimed in claim
 1. 15.The electronic component as claimed in claim 14, characterized in thatit is an organic light-emitting diode (OLED), organic integrated circuit(O-IC), organic field-effect transistor (OFET), organic thin-filmtransistor (OTFT), organic solar cell (O-SC) or organic laser diode(O-laser).
 16. An electronic component comprising a polymer or dendrimeras claimed in claim 10.